
<!DOCTYPE html>
<html lang="en">
 
<head>
  <meta charset="UTF-8">
  <meta http-equiv="X-UA-Compatible" content="IE=edge">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>change</title>
</head>
 
<body>
   
</body>
 
</html> 
<script>
  // 原生js封装一个字母翻转的函数？
  function fn(){
    var a=12,b='哈哈',t
    t=a;
    a=b;
    b=t;
    console.log(a,b);
  }
  fn()

</script>